Dental engine



(No Model.) I 2 Sheets-Sheet 1,

B. s. BROWN. .DENTAL ENGINE.

No. 561,561. Patented June 9, 1896.

witness as [nee/n20)". 4 $.S.Zrown- (N0 Modelfa 2 Sheets Sheet 2.

B. S. BROWN. DENTAL ENGINE.

Patented June 9, 1896.

witnesses. Invenior.

UNITED STATES f ATENT Urricn.

BENONI S. BROWN, OF ONSET, MASSACHUSETTS.

DENTAL ENGINE.

SPECIFICATION forming part a Letters Patent No. 561,561, dated June 9,1896. Application filed November 1, 1894. Serial No. 527,634. (Nomodel.)

To aZZ whom it may concern:

Be it known that I, BENONI S. BROWN, residing at Onset, in the county ofPlymouth and State of Massachusetts, have invented an Improved DentalEngine, of which the following is a specification.

Like letters and figures represent corresponding parts in the drawings.

My invention has for its Object, chiefly, to provide a dental enginewhose principal and bulky parts are placed out of the way of theoperator and adapted to have the desired parts swung into position foruse.

A bracket attached to the wall or standard supports ahorizontally-swinging frame hinged thereto. A vertically-rotating driving-wheel and a vertically-swinging and counterbalanced extension-arm arepivoted to said frame, the extension-arm being adapted to hold a framecarrying a rotatable spindle to which is attached a flexible shaftoperatively connected to a dental handpiece, or a frame in which revolvethe guide pulleys for carrying the belt or cord from which is suspendedand operatively connected a dental handpiece for like purpose. Thedriving-wheel may be operated by a crank and pitman or, preferably, by awrist connection pivoted on a wrist-pin, which can be attached to one ofthe arms of the wheel and be connected bya vertically-acting rod orchain to a crank at tached to a horizontal rock-shaft, which can passunder the'chair and is actuated by a treadle.

Figure 1 represents a general elevation of the entire engine as seenfrom in front of the chair and looking toward it, and is intended toshow the rock-shaft and crankat or about the center of their paths ofoscillation; Fig. 2, a View of the supporting-arm and counterweight;Fig. 3, enlarged detail'of the end of the supporting-arm and thespindle, to which may be attached a flexible driving shaft; Fig. 4,enlarged detail of end of supportingarin, showing the guide-pulleys of asuspension-handpiece; Figs. 5 and 6, enlarged detail of actuating-crank;Fig. 7, enlarged detail of treadle-crank; Fig. 8, top elevation of theframe, bracket, wheel, supporting-arm,

and spindle; Fig. 9, end View of driving-wheel and its frame, showingthe latter in section,

7 Fig. 10, front View of bracket; Fig. 11, top View of rock-shaft,universal joint, and treadle; Fig. 12, side View of treadle, its frame,and treadle-crank and pitman; Fig. 13, a section of the solid part F ofthe rock-shaft in perspective, showing channel or groove. Fig. 14 showsa section in perspective of the tubular part F of the rock-shaft withspline or feather inside. Fig. 15 is a front View of the universal jointwith a section of the rockshaft. Fig. 16 is a side View of the same,showing the bracket in section. Fig. 17 shows the telescoping joint ofthe rocking shaft with hollow part in section and solid part partly insection. Fig. 18 is a sectional View of the joint between the hollowpart of the rockshaft and the solid section L, showing the collar on thelatter; Fig.19,ele vation of chain; Fig. 20, elevation of connecting-rod9. Fig. 21 shows a modified form of actuating-crank. Fig. 22 shows thepins in. section.

A is the bracket supporting the engineframe B. It has suitable holesthrough it which receive screws for attaching it to a wall, a door, orwindow-frame, a strip of wood Q, attached to the wall, or it can besecured to an independent upright secured to the floor at its base. Thebracket has lugs 6 6, provided with holes to receive the pins T T.

The frame 13 can be stationary or can be hinged to the bracket A in anywell-known manner, so as to swing horizontally, as shown, and has lugs tt, with holes to receive the pins T Tfor that purpose. Alon g pin 0 isinserted into the frame near its top, and over this pin is hooked oneend of the off-center spring S.

The driving-wheel G can be pivoted tothe frame Bin any suitable way. Itis here shown pivoted to one side by a pin a, passing through its centerand through a boss on the frame B. The end of this pin can be threadedto receive a nut.

The wrist connection 1) is pivotally mounted on the wrist-pin or screw2, which in the form here shown is inserted in one of the arms of thewheel C. The wrist connection has two eyes or hooks a and (I inserted inits periphery.

The spring S is for the purpose of keeping the wheel 0 off from thedead-center, and

taken through the dotted line 2 .2, Fig. 8'

so that it can be readily started. It has hooks at each end whichengage, respectively, with the pin 0 and with the hook or eye a.

The connecting-rod g has hooks at each end, and these hooks engage withshort chains 7' 4' attached, respectively, to the hook (Z on the wristconnection and to the hook at on the pitman N of the actuating-crank Mor to its modification V. A single long chain instead of the rod and twoshort chains can be used with good effect and is simpler. The object ofthe chains 7' r is to give the rod great freedom of motion, and thusprevent any strain or binding when the rod g is out of the plane ofrotation of the wheel 0.

The supporting-arm G G G can be counterbalanced by a weight or bysprings in any well-known way. It is telescopic and is pivoted to theframe B opposite the wheel Cand in line with the axis thereof, so thatwhen it swings vertically the length of the drivingcord 0, whichconnects the drive wheel 0 with the spindle 0 will not be affected. Thesection G of the arm is secured to the frame B by the pin to, passingthrough it, and is held by a washer q and a nut w, screwed to the pin a,not tootight to preventits free motion, and it is made preferably solid,curves toward the wheel, and then in line with it, and terminates in acylindrical end 3, which fits snugly into the rear of the part G. Thesection G is tubular, split at its forward end, which has ears or lugsthrough which a thumbscrew m passes for the purpose of tightening itupon the section G which slides within it, thus making the armadjustable to various lengths or distances that the chair may be fromthe bracket. The section G2 is preferably entirely tubular and isadapted to receive the cylindrical arm of the frame of the spindle-headO of the usual flexible drivingshaft for driving the drill of anordinary dental handpiece. The section G2 is also adapted to receive theframe R, carrying the guidepulleys over which pass the driving-cord tooperate a suspension handpiece, thus enablin g either of the devicessupported in said section G to have a swinging motion at right angles tothe supporting-arm.

The weight W is slotted to receive the ex tension 7 of the part G, onwhich it slides, and has a set-screw inserted in it, which bears againstsaid extension and secures the weight in any proper position which maybe necessary to counterbalance the entire arm and its attached drillmechanism.

The rock-shaft F F L can be in one piece, but is preferably made insections. The section. L is solid, journaled in bearings 19 b on abase-plate II, and bent at right angles to form a crank L, which isbored out longitudinally from its outer end to receive a swivel L (seeFig. 7 which is slotted lengthwise thereof and bored transversely topivotally seat the lower end of the treadle-pitman 5. The opposite endof the section L is provided with a short collar o,slightly smaller indiameter than the inside of the hollow section F, which it enters, andis pivotally secured therein by a pin passing through both, as shown inFig. 18, thereby permitting it to have a slight play at angles to thesaid section F. This prevents any strain on the bearings, which mightoccur were the rock shaft in one piece. The section F has a feather orspline secured to its interior at the end adjoining the section F. Thesection F is preferably solid and slides within the section F for thepurpose of adjusting the entire shaft to different distances which thechair may be from the wall, and it has a channel or groove y, into whichenters the spline cc of the section F to prevent the two sections fromrotating upon each other, and is turned off at one end to form a journalwith a shoulder which is rotatively seated in the part K. (See Figs. 15and 16.) The part K is pivotally connected to the part J in such amanner as to permit the rock-shaft journaled therein to be verticallyrocked therein in line with its axis, while the said part J is pivotallyconnected to the bracket I, (which is adapted to be attached to the wallor a standard,) so as to permit said shaft, its base-plate, and treadlemechanism connected therewith to be swung horizontally in eitherdirection,

thereby affording means for locating saidshaft and treadle mechanism inproper relation to the operators chair and the tool-carrying arm of theengine in whatever position they are made to assume. It is not essentialthat this exact form of universal joint be used; but a ball-and-socketjoint or any wellknown form of the same will answer.

The actuating-crank M M is fastened to the section F near the universaljoint. Its end is swiveled axially in well-known way, as shown in Figs.5 and 6. In the construction here shown the crank-arm M is boredlongitudinally from its outer end to receive a swivel-section M, whichis slotted lengthwise thereof and bored transversely to pivotally seatthe lower end of the pitman N N. This construction and arrangementpermits the pitman to have three movements-win, a vertical one when theshaft F F L is rocked and two horizontal in vertical planes, oneparallel with the axis of said shaft and the other at right anglesthereto'thus allowing the said crank-arm to have awide range ofpositions relative to the drive-wheel crank or wrist-pin without causingany strain or unnecessary friction. The part N has a hook n formed atone end. The other end is screwthreaded and enters the part N, thusenabling the length of the pitman to be adjusted slightly by screwing orunscrewing it.

The connections between the rock-shaft F F L and the driving-wheel G canbe adjusted to various distances mainly by hooking the lower chainconnection 1" over the hooked pit man N, which may be raised or loweredto complete said adjustment. This process is the same whether theconnection is formed by a rod and two short chains or by a single longchain, as previously described.

The base-plate H has the treadle-base h pivoted thereto at its outeredge by a pin or screw 2. The treadle-base h has standards a e, to whichthe treadle E is hinged. The treadle-base and treadle can be swunghorizontally into any convenient position desired by the operator. A

The treadle E is connected to the crank L by a short pitman Z, roundedat its top end to fit a proper bearing in the toe of the treadle, towhich it is secured by a screw 3, which enters-it and holds it in place,yet allows the treadle to swing freely around it, while its opposite endis flattened, enters a slot in the swivel end of the crank-arm L, and ispivoted thereto, as previously described.

The modified form of actuating crank-arm V is a simple arm with a hookedend adapted to receive a link of a chain, which can have a free motionin any direction.

The advantage of my invention will be readily seen, as from thedescription the drivin g-cord passes from the drivin g-whee1 to thepulley on the spindle-head or over the guidepulleys 011 the suspensionarrangement, thus actuating a suitable drill carrying handpiece; thatthe driving-wheel and frame can be swung against the wall or out of theway; that the carrying-arm can be extended, raised, or lowered into aconvenient position for use or moved out of the way; that the rock-shaftcan pass under the chair or in front of it and extended to suitdifferent distances, and the treadle may be moved into any positionwithout any of the parts obstructing the operator,

and that the drive-wheel, by its chain connection with the swiveledactuating-crank (or its modification) attached to the rock-shaft, can

be operated by the treadle in whatever position said wheel androck-shaft may assume relative to each other.

Dental engines having the driving-Wheel rotating in a swinging bracketattached to the wall and engines having telescopic supporting-arms areold; so is the off-center spring and the weight and cord to balance saidarm.

I claim- 1. In combination with the driving-wheel of a dental engine, amovable base-plate, a double-cranked rock-shaft having one end journaledin the base-plate and a universal joint at the opposite end, a bracketor standard connected with said joint, a treadle for actuating therock-shaft and a means for connectin g the drivin g-wheel with therockshaft.

2. In a dental engine, the combination with the drive-wheel of a movablebase-plate, an extensible double cranked rock-shaft the rock-shaftprovided with a universal joint at one end and the opposite endjournaled in the base-plate, a bracket or standard connectcd with saidjoint and a treadle for actuating the rock-shaft.

3. I11 a dental engine the combination with.

the drivawheel, of a movable base-plate a double-cranked rock-shafthaving a telescopic section adapted to move lengthwise, a jointedsection adapted to move at an angle with the shaft, a universal joint atone end, the opposite end journaled in the base-plate, a bracket orstandard connected with said joint a treadle for actuating the shaft andmeans for operatively connecting the rockshaft with the drive-wheel; .1

4:. I11 a dental engine the combination with the drive-wheel thereof, ofa movable baseplate a rock-shaft consisting of a tube, the spline withinthe tube, a grooved cylinder sliding within the tube having the grooveadapted to fit the spline, a universal joint at one end of the shaft andhaving the opposite end journaled on the base-plate a bracket orstandard connected with the joint a treadle for actuating the shaft anda means for operatively connecting the rock-shaft with the drive-wheel.

5. In a dental engine, the combination with the drive-wheel thereof of amovable baseplate, a rock-shaft, a universal joint at one end of theshaft and the opposite end journaled in the base-plate a bracket orstandard connected with said joint a crank on the shaft near theuniversal joint, the end of the crank swiveled so as to turn at rightangles thereto the pitman pivoted therein and having a hooked andscrew-threaded section whereby the pitman can be adjusted in length atreadle for actuating the shaft and a means for operatively connectingthe rock shaft with the drive wheel.

6. The combination with the drive-wheel of a dental engine of abase-plate a doublecranked rock-shaft having one end j ournaled in saidplate a supporting-bracket a universal joint connecting the opposite endof said shaft and the bracket and comprising a block or bearing adaptedto swing vertically in another block pivoted to said bracket andswinging horizontally thereon said bracket being adapted to be securedto a wall or standard or formed on the latter a treadle for actuatingthe shaft and means for operatively connecting the rock-shaft and drive-wheel substantially as described.

7. In combination with the drive-wheel of a dental engine, a base-plate,a rock-shaft having one end j ournaled in said plate, asupporting-bracket, a universal joint connecting the opposite end ofsaid shaft and the bracket,

said bracket being adapted to be secured to a wall or a standard orformed on the latter, a treadle-crank at or near one end of the shaftand a sectional actuating-crank at or near its opposite end saidactuating-crank having its outer section or end pivoted axially so as tobe adapted to oscillate in a horizontal direction lengthwise with theshaft, a pitman pivoted or journaled in said outer section and adaptedto rock or oscillate in a horizontal direction at right angles to theshaft, a treadle for operating the shaft, and a means foroperativelyconnecting the shaft with the drivewheel substantially asdescribed and shown. 8. In combination with the drive-Wheel of a dentalengine a movable base-plate, a dou- 5 ble-cranked rock-shaft,l1aving;one end journaled inthe base-plate and a universal joint at the oppositeend, a bracket connected With said joint and adapted to be attached to aWall or standard 01' formed on the latter a treadle for actuating therock-shaft and a IO chain for connecting the drive-Wheel with therock-shaft substantially as described.

B. S. BRO\VN. Vitnesses:

ARTHUR B. TIAMMOND, E. G. PAnsoNs.

